DCEA_white_paper.pdf

8/11/2019 DCEA_white_paper.pdf

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A White Paper from the Expertsin Business-Critical ContinuityTM

Data Center Assessment HelpsKeep Critical Equipment Operational


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Executive Summary

The IT infrastructure within many companies has evolved into an interdependent,business-critical network that relies on the data center as its hub. Growing businessdemands are forcing data center managers to support more equipment, resulting inincreased heat loads. Corporate attention on the data center is also driving the need for

greater flexibility balanced against high availability and the lowest total cost of ownership.


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Introduction

Availability of mission critical IT equipmentis influenced by many factors, includingdesign issues and operation and maintenancepractices. The infrastructures design was

probably appropriate when the equipmentwas originally installed, but changing needsand technology shifts may have made thesystem less than optimal. For example,new high-performance equipment, suchas dual-processor servers and high-speedcommunications switches, are raising rackdensities well above 30 kW.

Other factors can influence systemperformance, such as moving or changing

computer equipment without consideringthe underlying support strategies.Obstructions such as abandoned cablingcan reduce air flow for cooling systems,as shown in Figure 1. Even new facilitiescan experience nagging cooling problemsthat create continuity risks or interfere withfacility performance.

Figure 1. Disorganized cable managementunder floor tiles can impede coolingto equipment.

Conducting a critical assessment of existingcooling strategies can enhance the datacenters operational performance and expose

vulnerabilities within existing cooling orelectrical systems. Cooling modules havemoving parts that eventually wear out andtransitioning from a break/fix mindset to amore proactive approach or instituting apreventive maintenance program willhelp ensure that components last longerand perform within their designatedoperating parameters.

Taking a proactive approach will also helpprevent costly downtime of business criticalequipment. According to a 2006 Emersonbusiness continuity survey, 38 percent oflarge businesses estimate that a full businessday of downtime could cost them more than$500,000 in lost revenue.

A data center assessment will help identify,evaluate and resolve cooling vulnerabilitiesthat could adversely affect the data centersoperational performance or energy efficiency.The assessment will determine whetherheat is being removed from sensitive heat-generating computer equipment andexamine the capacity of existing electricalsystems and the quality of power providedto the data center.

Thermal Assessment

Taking temperature readings at critical pointsis the first step in identifying hot spotsand resolving problems that could result inequipment degradation. These readings willdetermine whether heat is being successfullyremoved from sensitive heat-generatingcomputer equipment, including blade servers.

The latest generation of blade servers

pushes power and heat levels even higherthan in the past. A single rack loaded withfour fully configured IBM BladeCenterH Chassis each drawing 5.8 kW createsa load of almost 24 kW in an enclosure thatoccupies just seven square feet of data

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A data center assessment

will help identify,

evaluate and resolve

cooling vulnerabilities

that could adversely

affect the data centers

operational performance

or energy efficiency.


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center floor space. This contrasts sharply withthe state of the industry in 2000 when theaverage rack consumed just 1 kW of power.

Communications equipment is also pushingheat to new levels. Depending on its power

supply configuration, the Cisco CRS-1 router,for example, creates a heat load of 15 to16.6 kW per rack.Annual infrared inspections are recommendedby ANSI/NFPA 70B Electrical EquipmentMaintenance Standard and most insurancecompanies and are performed whileequipment is energized and operatingso there is no disruption of operations.

Components typically tested during aninfrared inspection include transformers,capacitor banks, switches, fuses, circuitbreakers, bus bars, cable splicing andmotors. UPS equipment, batteries, cooling,generation and power conditioningequipment, switchgear and DC powerequipment should also be infrared inspected.

Findings from infrared inspections are carefullydocumented with high-resolution colordigitized photographs and thermograms,

along with recommendations for correctionsor repairs.

Introduction of high-density servers and/ordata center consolidation can create anunbalance between the equipment loadand unit air capacity. Taking airflowmeasurements will help identify raisedfloor air patterns, under-floor obstructionsand airflow through computer racks.An assessment of the data centers vaporbarrier will also be conducted to ensureoutside areas are not influencing the datacenter. Infiltration of outside air can increasecomputer room air conditioning (CRAC)unit operating costs through unnecessaryhumidification or dehumidification.

In addition, the assessment will alsocompare the equipment load with unitair capability. CRAC unit performance isalso evaluated to ensure the unit is beingmaintained, performing properly and is stillreliable. Computational Fluid Dynamics (CFD)

combined with air flow measurements is thebest tool for demonstrating and analyzing airflow characteristics within the data center, asillustrated by the air flow patterns in Figure 2.CFD is a simulation tool designed to createa better understanding of why hot spots arepresent and illustrate the effects of under-floor obstructions on air flow. The tool visuallydepicts heat-related risks in the data centerthat can interfere with facility performance.

Figure 2. Computational Fluid Dynamics is asimulation tool designed to demonstrate theair flow characteristics of a raised floor. CFDprovides a better understanding of why hotspots are present and the effects of under floor

obstructions on air flow.

Once temperature and air flow problems areidentified, data center managers can worktoward eliminating hot spots by adjustingair flow patterns and hot aisle/cold aisleconfigurations. Using supplemental coolingmay also be necessary.

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Computational Fluid

Dynamics (CFD)

combined with air

flow measurements

is the best tool for

demonstrating andanalyzing air flow

characteristics within

the data center.


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Electrical Assessment

The electrical assessment is a critical partof the overall data center assessment sincebusinesses have a 30 percent probability ofexperiencing power quality problems if their

facility is more than five years old and hasundergone significant changes. Evaluatingthe electrical system onsite, as seen in Figure3, will help determine whether it is adequatefor the data center now and in the future.Analyzing the integrity of the facilitys powersystem will also help maximize availability ofthe mission-critical infrastructure.

Figure 3. An electrical assessment can evaluatethe integrity of a facilitys power system tomaximize availability of mission-criticalinfrastructure.

The following actions are included in anelectrical assessment.

Conduct a single point of failure analysis toidentify critical failure points in the system.

Identify capacity of all switchgear from themain PDU to mission-critical PDUs (voltage,amperage, phase).

Determine the current that is drawnthrough all UPS equipment and breakersfrom the main PDU to mission-criticalPDUs. The current will be determined byreading exiting meters, if available, or using

a clamp-on amp meter. Compare the measured current and

power-rating for all breakers from themain PDU to mission-critical PDUs.Any imbalances will be pinpointedand areas of concern noted.

Determine the kW and KVA leading on eachUPS and compare to the UPS rating.

Evaluate the rated capacity of eachgenerator vs. UPS capacity ratings.The generator full load rating should be

less than 150 percent of the UPS rating. Perform a harmonic snapshot at the main

breaker switchgear and the load side ofeach UPS to identify any anomalies.

Confirm that breakers are labeled downto the PDU.

Determine the load per rack and/orPDU. This measurement may not bepossible without risking a shut down ofthe connected server loads. If this riskexists, the measurement will not be taken.Instead, the Full Load Amperage (FLA)rating of equipment within the racks willbe documented and added to the analysis.

It is important to note that power usagemeasurements taken during the electricalassessment are valid only for the instant themeasurement is taken. IT equipment maybe more fully utilized at other times, whichwould affect the measurements.

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The electrical

assessment is a critical

part of the overall data

center assessment

since businesses have a

30 percent probability

of experiencing power

quality problems

if their facility is more

than five years old

and has undergone

significant changes.


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Data Center Assessment Reporting

At the conclusion of the data centerassessment, a comprehensive report will beprovided that includes single points of failureand any potential power issues surrounding

harmonic distortion, voltage regulation andload imbalance. A detailed facility floor planwill show the location of existing equipmentserver racks and airflow obstructions, witha CFD report showing airflow characteristicsof the space and CRAC unit performance.

The final report will include specificrecommendations for improvement,which can be used to eliminate hot spots,advance air flow, improve vapor barrier,

and reduce heat within the data center.Recommendations for improvement willhelp maximize system availability nowand in the years ahead.

Conclusion

Data centers are dynamic environmentswhere heat loads are constantly increasingand challenging cooling strategies. Ongoingtechnology shifts and blade servers create

extreme heat densities and hot spots thatmust be detected and corrected before theyresult in component failure and downtime.

A critical assessment of cooling strategies combined with a thorough preventivemaintenance program can protectthe data center investment and increasedata center availability, performance andenergy efficiency. These tactics can alsoprovide the peace of mind that comes with

knowing that data center equipment willprovide the high level of availability criticalto business continuity.

For more information about conducting acritical assessment of cooling strategies orimplementing a preventive maintenanceprogram, contact an authorized servicerepresentative or visit Liebert.com.

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A critical assessment

of cooling strategies

combined with a

thorough preventive

maintenance program

can protect the datacenter investment

and increase data

center availability,

performance and

energy efficiency.


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Emerson Network Power.The global leader in enabling Business-Critical Continuity. EmersonNetworkPower.com

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Connectivity

DC Power

Embedded Computing

Embedded Power

Monitoring

Outside Plant

Power Switching & Controls

Precision Cooling

Racks & Integrated Cabinets

Services

Surge Protection

Emerson Network Power

1050 Dearborn DriveP.O. Box 29186

Columbus, Ohio 43229

800.877.9222 (U.S. & Canada Only)

614.888.0246 (Outside U.S.)

Fax: 614.841.6022

EmersonNetworkPower.com

Liebert.com

While every precaution has been taken to ensure accuracy

and completeness in this literature, Liebert Corporationassumes no responsibility, and disclaims all liability fordamages resulting from use of this information or forany errors or omissions. Specifications subject to changewithout notice. 2007 Liebert Corporation. All rightsreserved throughout the world. Trademarks or registeredtrademarks are property of their respective owners.Liebert and the Liebert logo are registered trademarksof the Liebert Corporation. Business-Critical Continuity,Emerson Network Power and the Emerson Network Powerlogo are trademarks and service marks of Emerson ElectricCo. 2007 Emerson Electric Co.

WP154-117SL-24618

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